Posted on October 12, 2010 at 13:22hi.
i am trying to activate the adc module with the following program :
__IO uint16_t ADCConvertedValue;
int main(void)
{
int temp=0;
setsystemclock(); //set system clock to 24Mhz3
//rcc CONFIGURATION
RCC->AHBENR=RCC_AHBENR_DMA1EN; //dma clock enable
RCC->APB2ENR=RCC_APB2ENR_IOPCEN | RCC_APB2ENR_ADC1EN; //portc and ADC clock enable.
//GPIO CONFIGURATION
GPIOC->CRL=0x0;// ADC1_IN14
// DMA configuration:
DMA1_Channel1->CCR= DMA_CCR1_CIRC | DMA_CCR1_PSIZE_0 | DMA_CCR1_MSIZE_0 | DMA_CCR1_PL_1; //Circular mode,Read from peripheral,Peripheral size 16-bits, Memory size 16-bits, Channel priority level High.
DMA1_Channel1->CNDTR=1; //bytes to be transmitted. Check only 1 channel
DMA1_Channel1->CPAR = 0x4001244C; //adc address
DMA1_Channel1->CMAR=(uint32_t)&ADCConvertedValue;
DMA1_Channel1->CCR |= CCR_ENABLE_Set;
//ADC configuration
ADC1->CR1=ADC_CR1_SCAN;
ADC1->CR2=ADC_CR2_ALIGN | ADC_CR2_EXTSEL ; //data align right , software start
ADC1->SMPR1=0;// 1.5 cycles conversion time
ADC1->SQR3=0;
ADC1->SQR1|=ADC_SQR1_SQ14_0;
ADC1->CR2 |=ADC_CR1_SCAN ; /* Enable ADC1 DMA */
ADC1->CR2 |=ADC_CR2_ADON; /* Enable ADC1 */
ADC1->CR2 |=ADC_CR2_RSTCAL ;//reset calibration
while ((ADC1->CR2 & ADC_CR2_RSTCAL) != 0x00); //wait for end of ADC1 reset calibration register
ADC1->CR2 |=ADC_CR2_CAL;/* Start ADC1 calibaration */
while((ADC1->CR2 & ADC_CR2_CAL) != 0x00);/* Check the end of ADC1 calibration */
ADC1->CR2 |=ADC_CR2_SWSTART |ADC_CR2_EXTTRIG; /* Start ADC1 Software Conversion */
while(1)
{
if((ADC1->SR&ADC_SR_EOC)>0)
{
temp=ADC1->DR;
ADC1->CR2 |=ADC_CR2_SWSTART |ADC_CR2_EXTTRIG; /* Start ADC1 Software Conversion */
temp=temp+1;
}
}
}
but if i put GND in PC4 which is channel 14 i dont get zero in ADC1->DR.
why what am i doing wrong?
thanks.
